Gas-fired radiator tube



Bully M 393% W. M. HEP BURN ET AL GAS-FIRED RADIATOR TUBE Original FiledMarch 26, 1934 4E mwV v A Patented July 14, '1936 UNITED STATES PATENTOFFICE GAS-FIRED 'RADIATOR TUBE poration of New York Application March26,

1934, Serial No. 717,460

Renewed April 8, 1936 11 Claims.

The present invention has for its object to provide improvements in waysand means for burning relatively large quantities of fuel in arelatively restricted combustion chamber such as a relatively long tubeor conduit and in a manner to obtain uniform heating and hightemperatures throughout a relatively great distance from the point wherethe fuel initially begins to burn.

' In accordance with the present invention the fuel to be burned and itscombustion-supporting air are separately flowed into one and the sameend of the combustion tube; a power-operated suction-producing device isprovided at the exhaust end of the tube for pulling thecombustionsupporting air into the tube, and means are provided forconstantly insuring ignition of the air and fuel where they initiallyintermix in combustible proportions.

The important advantages attained by firing the tube in the manner thusbriefLv indicated may be briefly stated as follows: By delivering thefuel and air to the combustion tube in separate streams combustionproceeds relatively slowly as compared with combustion of a preformedmixture of air and gas; by drawing or pulling the air into the tube boththe air and the gas tend to flow in parallel streams with lessturbulence than would be the case if the air were pushed or forced intothe tube; by constantly insuring ignition of 39 the air and fuel wherethey initially intermix in combustible proportions the rate of flow ofthe air and gas as a factor bearing on the problem of keeping the airand gas ignited is automatically eliminated, it being understood that inthe absence of means for constantly insuring ignition the rate of flowwould necessarily have to be low enough to prevent the flame from beingpulled away from the discharge end of the fuel supply tube; and byutilizing a power-operated suctionproducing device for pulling the airinto the tube, the rate of flow of the air can be readily varied andmaintained constant at any particular rate and the amount of fuel thatcan be burned is greatly in excess of what could be burned if ordinarystack draft were relied on to pull the combustion-supporting air intothe tube.

For a more complete understanding of the in-.- vention, reference ismade to the following description taken in connection'with theaccompanying drawing wherein the preferred form of the invention isshown.

In the drawing,- Fig. 1 shows the radiator tube as straight throughoutits length and how it may be utilized for heating a closed chamber 8,the tube being broken at two points in its length to indicate that it isof relatively great length, the mechanism at the exhaust end of the tubebeing in section;

Figs. 2 and 3 show how the invention may be 5 utilized for heating atank 9 and a circular chamber 8' respectively, and

Fig. 4 is a. sectional view of the apparatus associated with the fuelintake end of the tube.

The radiator tube is indicated at 5 and its in- 10 take and exhaust endsat 6 and 1, respectively. At the outset, it may be stated that it isquite immaterial to the present invention whether the radiator .tube bestraight throughout its length;

but if it is not straight throughout its length, it 15 should bestraight for a substantial distance from the fuel intake end thereof inorder that intermixing of. the air and fuel shall not be unduly.accelerated in the first portion of the tube.

Coupled to the exhaust end 1 of the radiator 20 tube is a power-operatedsuction-producing device shown as comprising a chambered fitting l0, aneductor tube Ii supported by and extending i fromthe fitting, and a jetorifice nozzlc I2 positioned to discharge intothe mouth of the eductor25 tube, air or other fiuid under pressure being delivered to the nozzle12 by a pipe l3 provided with a flow controlling valve. The means fordelivering fuel to the radiator tube is generally indicated at E8 andwill now be described. v 3

Coupled to the intake end 6 of the tube 5 is a tubular fitting I9whichconstitutes in effect an extension of the tube. The fuel to beburned is discharged straightforwardly into the radiator tube by a tubeor conduit 24 of relatively large cross sectional area wherebyrelatively large volumes of fuel under moderate pressure can bedischarged into the radiator tube with minimum turbulence. The fuel tube24 is shown as leading from the chamber 30 to which fuel is supplied bya fuel supplypipe IS. The air for supporting combustion of the fueldischarged from the tube 2'4 enters the tubular fitting l9 through anannular passage 2| at the front end thereof, the air being drawn orpulled in by the operation of the power-operated, suction-producingdevice at the exhaust end of the radiator tube. In view of the fact thatthe air and fuel are separately introduced into the radiator tube, andin further 50 view of the fact that the air is pulled into the tube andin further view of the fact that the cross sectional area of theradiator tube is relatively restricted where the fuel and air initiallyintermix in combustible proportions, it is essential to 66 thesuccessful operation of the apparatus that means be provided forconstantly insuring ignition of the air and fuel where they initiallyintermix in combustible proportions.

In accordance with the present invention, ignition-of the air and fuel,where they initially intermix in combustible proportions, is effected bydischarging between the air and fuel a burning stream of combustiblemixture, the mixture being discharged from an annular passage 26 aroundthe fuel tube 24 inwardly of the discharge end of the latter; andignition of the combustible mixture is constantly insured by maintaininga ring of flame in an annular combustion groove 28 at the discharge sideof the passage 26, this ring of flame being produced by dischargingcombustible mixture from a plurality of discharge orifices 29 whichdeliver into the combustion groove 28, a mixture supply chamber beingindicated at 25., The outlet from the combustion groove 28 is an annularpassage 21 around the discharge end of the fuel tube 2|. The combustiongroove 28 and orifices 29 are preferably formed in a hub 22 whichisintegral with the tubular fitting R9. The hub is extended outwardly inthe form of a sleeve and detachably mounted on this sleeve is a body 23which cooperates with the sleeve to form the mixture supply chamber 25.Mounted on the body 23 is an air shutter 20 which is adjustable tocontrol the effective inlet area of the air passage 2 I.

The means for delivering combustible mixture to the chamber 25 may be ofany preferred form and as shown in Fig. 1 comprises a mixing device IEto which air is delivered by a pipe i4 and to which gas is delivered bya pressure regulator ll shown as connected at its inlet end to the fuelsupply pipe l5. Mixing apparatus of this type is well known in the artand, therefore, need not be further described.

A radiator tube fired in accordance with the present invention has wideutility in industrial heating operations and-marks an importantimprovement in the art of burning fluid fuel.

What is claimed is:

l. The combination of a heat-radiating tube, and means for internallyfiring the tube comprising: means for flowing a stream of fuel gas as acore into one end of the tube, means for flowing a burning stream ofcombustible mixture into the same end of the tube as a sheath aroundsaid stream of fuel gas, and power-operated suction producing means fordrawing combustion supporting air into the tube as a sheath around theburning combustible mixture.

2. The combination of a heat-radiating tube, and means for internallyflring the tube comprising: means'for flowing a stream of fuel gas as acore into one.end of the tube, means for flowing a stream of burningcombustible mixture into the same end of the tube as a sheath aroundsaid stream of fuel gas, and means including entraining apparatus at theother end of the tube for drawing combustion supporting air into thefuel intake end of the tube as a sheath around the burning combustiblemixture.

3. In apparatus of the class described, the combination of a relativelylong tubular conduit open at both ends to the open air, means includinga tube having i s outlet inside of one end of said conduit fordelivering to the conduit a stream of fluid fuel in greater volume thancould be burned with natural draft through the conduit, a poweroperatedsuction-producing device forming part of the discharge end of saidconduit for positively pulling into the fuel intake end of the conduitthe required amount of air for supporting proper combustion of the fuel,and means surrounding said tube for constantly insuring ignition of thefuel and induced air where they initially intermix in combustibleproportions.

4. In apparatus of the class described, the combination of a relativelylong tubular conduit open at both ends to the open air, means includinga tube having its outlet inside of one end of said conduit fordelivering to the conduit a stream of fluid fuel in greater volume thancould be burned with natural draft through the conduit, 2. poweroperatedsuction-producing device forming part of the discharge end of saidconduit for positively pulling into the fuel intake end of the conduitthe required amount of air for supporting proper combustion of the fuel,and means at the fuel intake end of the conduit for discharging flaminggases between the respective air and fuel streams to constantly insureignition thereof where they initially intermix in combustibleproportions.

5. In apparatus of the class described, the combination of a relativelylong tubular conduit open at both ends to the open air; means includinga tube for delivering to the conduit a stream of fluid fuel in greatervolume than could be burned with natural draft through the conduit, apoweroperated suction-producing device forming part of the discharge endof said conduit for positively pulling into the fuel intake end of theconduit the required amount of air for supporting proper combustion ofthe fuel, and means surrounding said tube for constantly insuringignition of the fuel and induced air where they initially intermix incombustible proportions.

6. In apparatus of the class described, the combination of a relativelylong conduit; means for effecting the entrance into said conduit at theintake end thereof of substantially non-turbulent streams of combustionsupporting air and gas whereby combustion is substantially dependentupon the inter-diffusion of said streams; and means eflective betweensaid streams, operable independently of said streams, and arranged tocontinuously create a zone of ignition extending therebetween.

7. In combination, a radiator tube, and means for burning a greatervolume of fuel therein than could be burned with natural draft throughthe tube comprising: suction-producing means coupied to the exhaust endof the tube for inducing combustion supporting air to enter the intakeend of the tube, means at the intake end of the tube for discharging thefuel thereinto in the form of a stream which tends to maintain itsintegrity for a substantial distance from its point of discharge fromsaid means, and igniting means continuously operable independently ofsaid fuel and air to create a zone of ignition extending lengthwise fromadJacent the inlet end of said tube, thereby constantly insuringignition of the fuel and induced air as and when they initially intermixin combustible proportions.

8. In combination, a radiator tube, and means for burning a greatervolume 'of fuel therein than could be burned with natural draft throughthe tube comprising: suction-producing means coupled to the exhaust endof the tube for inducing combustion supporting air to enter the intakeend of the tube, means at the intake end of the tube for discharging thefuel thereinto in the form of a stream which tends to maintain its 75flaming gases are drawn forwardly. to form the zone of ignition.

9. The combination with a radiator tube whose length is many timesgreater than its diameter and whose diameter is small enough to permitthe tube to be utilized either as a straight or bent heating element ina heating chamber, of means for internally firing the tube in a mannerto produce delayed combustion therein comprising means for releasingunignited gaseous fuel adjacent the intake end of the tube as a streamwhich tends to maintain its stream integrity for a substantial distancefrom its point of release in the tube, regulable means for producing anegative pressure at the discharge end of the tubeto cause air atatmospheric pressure at the intake end of the tube to flow thereinto andto flow along with the fuel to support combustion thereof, and acontinuously operable igniter adjacent the intake end of the tube forcontinuously igniting the incoming fuel as it intermixes with theincoming air.

- 10. The combination witha radiator tube whose length is many timesgreater than its diameter and whose diameter is small enough to permitthe tube to be utilized either as a straight or bent heating element ina heating chamber, 'of means for internally firing the tube in a mannerto produce delayed combustion therein comprising means for releasingunlgnited gaseous fuel adjacent the intake end of the tube as a streamwhich tends to maintain its stream integrity for a substantial distancefrom its point of release in the tube, regulable means for producing a 5negative pressure at the discharge end of the tube to cause 'airatatmospheric pressure at the intake end of the tube to flow thereinto andto fiow along with the fuel to support combustion thereof, and acontinuously operable igniter adiacent the intake end of the tube forcontinuously igniting the incoming fuel as it intermixes with theincoming air, said igniter comprising means for burning an explosivemixture of fuel and air. 11. The combination with a radiator tube whoselength is many times greater than its diameter and whose diameter issmall enough to permit the tube to be utilized either as a. straight orbent heating element in a heating chamber, of means for internallyfiring the tube in a manner to produce delayed combustion thereincomprising means for releasing unignited gaseous fuel adjacent theintake end of the tube as a stream which tends to maintain its streamintegrity for a substantial distance fromits point of release in thetube, regulable means-for producing a negative pressure at the dischargeend of the tube to cause air at atmospheric pressure at the in take endof the tube to flow thereinto and to flow along with the fuel to supportcombustion thereof, and a continuously operable igniter adjacent theintake end of the tube for continuously igniting the incoming fuel asitintermixes with the incoming air, said'igniter comprising means for.discharging explosive mixture in the same direction of flow as saidfuel.

\ WILLIABKM. HEPBURN.

HUGH B. BARBER.

